|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Materials for High Temperature Applications: Next Generation Superalloys and Beyond
||Phase Evolution and Creep Properties of Nb-rich Nb-Si-Cr Eutectics
||Florian Gang, Alexander Kauffmann, Martin Heilmaier
|On-Site Speaker (Planned)
Nb-Si based alloys are promising novel materials for high temperature structural applications. Good mechanical strength and oxidation resistance can be achieved simultaneously by e.g. combining different phases in a very fine eutectic microstructure. Solely the ternary system Nb-Si-Cr exhibits a Nb-rich ternary eutectic. In this system, silicon is known to improve the creep properties by formation of silicides. Chromium is added to improve the oxidation resistance due to Cr<SUB>2</SUB>Nb Laves phase formation. However, the nominal compositions stated in literature are contradictory and report the presence of different phases. Therefore, the Nb-rich eutectic in the ternary system Nb-Si-Cr is determined experimentally. The phase evolution during solidification of different (near-)eutectic alloys is studied as well as the phase stability when employing heat treatments up to 1500 °C for several hundred hours. The resulting microstructures are comparatively assessed. Compressive creep test at 1200 °C give insights into acting creep deformation mechanisms.